Overview
Banker Sam Wheat and his artist girlfriend Molly Jensen settle into a loft in Manhattan with assistance from Sam's friend and colleague, Carl Bruner. One evening, the couple is accosted by a mugger in the street; although Sam seems to scare him off, he soon finds himself returning to a heartbroken Molly, who is holding his lifeless body. Realizing he is deceased, Sam notices a luminous light above him but chooses to walk towards Molly, causing the light to vanish.
As a spirit, Sam lingers beside Molly, feeling despondent and unable to interact with the physical realm. The other ghosts he encounters are of no help. Later, the mugger breaks into their apartment and searches it. Molly unexpectedly returns, and Sam startles her cat, which can perceive him; this causes the cat to attack the intruder, prompting him to flee. In his pursuit of the mugger, Sam is confronted by an aggressive ghost on the subway who can manipulate physical objects. He follows the mugger back to his place, discovering his name is Willie Lopez and that he was specifically targeted.
Eventually, Sam meets Oda Mae Brown, a fraudulent psychic who surprisingly can hear him. He insists that she help him alert Molly. After some reluctance, she agrees following a night of persistent singing from Sam. Despite her familiarity with Sam and Molly's bond, Oda Mae finds it challenging to persuade Molly of the reality of the afterlife until Sam has her use the word "ditto," which he always said in response to Molly's declarations of love. Molly informs the police and Carl about Willie, but they dismiss her claims and expose Oda Mae's criminal background, leaving Molly disillusioned.
Meanwhile, Sam observes Carl and discovers that he had enlisted Willie to rob Sam of a book containing important banking passwords. Carl intends to use these passwords to launder $4 million in drug money through an account under the alias "Rita Miller" for his criminal associates. He breaks into Molly's apartment to obtain the book and later tries to seduce her until a frustrated Sam unintentionally knocks over a picture frame. Sam then returns to the subway and persuades the aggressive ghost to assist him in honing his emotions, enabling him to interact more effectively with the physical world.
Sam goes to Oda Mae, who has gained popularity among ghosts seeking to connect with their living relatives, and convinces her to impersonate Rita Miller to withdraw the drug money, which she hesitantly gives to charity; Molly witnesses this transaction at the bank. As Carl grows frantic over the vanished funds and the threats from his criminal partners, Sam begins to haunt him. Carl visits Molly to discuss the haunting, during which she inadvertently reveals that Oda Mae withdrew the money. While Molly is upstairs, Sam confronts Carl, who threatens to kill Molly if the money isn’t returned that night. Carl and Willie go to confront Oda Mae, but Sam warns her to hide and terrorizes Willie, who ends up fleeing into traffic and is fatally struck by a car. Dark figures then appear to drag Willie's screaming spirit away.